Ferromagnetic materials, materials with a strong tendency to align atomic magnetic dipoles with strict parallelism, are indispensable to the operation of a wide array of retail and industrial devices. Such materials are strongly responsive to applied magnetic fields and can also be prepared to emanate stable, bulk magnetic fields themselves. As examples of applications, a wide array of electronic devices such as medical and scientific diagnostic devices, electronic data storage media, and electronic or electromagnetic beam-steering devices rely on ferromagnetic materials to function. Of particular interest are core-solenoid devices having ferromagnetic cores, such as electric motors and electric generators.
Conventionally, ferromagnetic materials are alloys or compositions consisting primarily of the inherently ferromagnetic elements such as iron, nickel, cobalt, as well as certain compositions of rare-earth metals. Because of the relatively high density of these elements, typically about 8 g/cm3 or 500 lb/ft3, devices which employ an appreciable amount of ferromagnetic material tend to be very heavy.
Automotive vehicles use ferromagnetic materials in a variety of ways, particularly in core-solenoid devices. These range from the relatively small, such as an alternator or an electric motor that operates a power window, to the relatively large, such as in the drive train of a hybrid vehicle or all-electric vehicle. The development of ferromagnetic (including ferrimagnetic) materials or compositions having much lower density than that of the inherently ferromagnetic elements can potentially decrease the weight and thereby improve the efficiency of such vehicles.
Previous disclosures have shown the preparation of magnetic nanoparticles, such as MnBi nanoparticles, using a family of novel reagent complexes. The preparation of bulk magnets from magnetic nanoparticles typically involves a step of binding, fusing, sintering, or otherwise attaching the individual nanoparticles to one another into a bulk composition. The particular process by which this is achieved can affect the magnetic properties of the bulk magnet. Methods for making a bulk magnet from magnetic nanoparticles which enhance the magnetic properties of the bulk magnet are to be desired.